Going to https://w3c.github.io/web-share/demos/share-files.html in desktop Safari 16.6 and clicking "Share" does not reveal the "Copy link"-button. Clicking "Edit extensions..." in the bottom of the native share-popover reveals the enabled "Copy link"-option, but it doesn't appear in the popover as expected.
<rdar://problem/114365267>
In Safari 17 on Ventura, the 'Copy link' option disappeared entirely and can no longer be found under "Edit extensions..." at all.
In desktop Safari 17.1 on Sonoma 'Copy link' has returned as an option under 'Edit extensions...', but even though the checkbox next to it is checked, it still doesn't appear when you use the api. https://w3c.github.io/web-share/demos/share-files.html